The present invention, in some embodiments thereof, relates to methods of classifying a subject as having benign multiple sclerosis or typical relapsing remitting multiple sclerosis and, more particularly, but not exclusively, to methods of treating multiple sclerosis based on same.
Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system (CNS) affecting young adults (disease onset between 20 to 40 years of age) and is the third leading cause for disability after trauma and rheumatic diseases, with an estimated annual cost 34,000 USD per patient (total life time cost of 2.2 million USD per patient).
The disease is characterized by destruction of myelin, associated with death of oligodendrocytes and axonal loss. The main pathologic finding in MS is the presence of infiltrating mononuclear cells, predominantly T lymphocytes and macrophages, which surpass the blood brain barrier and induce an active inflammation within the brain and spinal cord. The neurological symptoms that characterize MS include complete or partial vision loss, diplopia, sensory symptoms, motor weakness that can worsen to complete paralysis, bladder dysfunction and cognitive deficits, which eventually may lead to a significant disability. The associated multiple inflammatory foci lead to myelin destruction, plaques of demyelination, gliosis and axonal loss within the brain and spinal cord and are the reasons contribute to the clinical manifestations of neurological disability.
The etiology of MS is not fully understood. The disease develops in genetically predisposed subjects exposed to yet undefined environmental factors and the pathogenesis involves autoimmune mechanisms associated with autoreactive T cells against myelin antigens. It is well established that not one dominant gene determines genetic susceptibility to develop MS, but rather many genes, each with different influence, are involved.
Clinically, in 85% of MS patients the illness is initiated with a relapsing-remitting course (RRMS), and in about 10-15% of MS patients have an a-priori primary progressive course (PPMS) without relapses. RRMS is characterized by inflammatory attacks associated with neurological deficits with periods of remissions between the relapses that vary in time. After a period of 10 years, about 50% of RRMS patients will progress to a secondary progressive MS (SPMS) course, characterized by permanent neurological dysfunction, with or without relapses and progressive disability.
Benign MS (BMS) is a clinical variant of RRMS in which the patients develop low neurological disability if at all after a disease duration of at least 10 years. Accordingly, this group of MS patients do not experience devastating accumulating disability over-time and when these patients are examined neurologically and scored by the Expanded Disability Status Scale (EDSS) they receive a score that is equal to or lower than 3.0. This low EDSS score signifies mild disability and when this low disability occurs more than 10 years after disease onset, the course of MS is defined as benign (Pittock S J and Rodriguez M, 2008; Costelloe, L., et al., 2008). Prediction of patients that will have BMS is currently impossible and the definition of these patients is retrospective. The molecular events accountable for the BMS variant of disease are not understood.
Diterpenoid triepoxide Triptolide (TPT), isolated from the Chinese herb Tripterygium wilfordii (Leuenroth S J and Crews C M. Triptolide-induced transcriptional arrest is associated with changes in nuclear substructure. Cancer Res. 2008; 68:5257-5266) has various anti-inflammatory effects (Liu Y, et al. Triptolide, a component of Chinese herbal medicine, modulates the functional phenotype of dendritic cells. Transplantation. 2007; 84:1517-1526), it modulates T-cell inflammatory responses and ameliorates Experimental Autoimmune Encephalomyelitis (Wang Y, et al. Triptolide modulates T-cell inflammatory responses and ameliorates experimental autoimmune encephalomyelitis. J Neurosci Res. 2008; 86:2441-2449). Derivatives of TPT were suggested for treating autoimmune diseases (EP 0983256, PCT/US1998/008562; WO9852933A1).
Cycloheximide, inhibits the phosphorylation of RRN3 and causes its dissociation from RNA polymerase I. RRN3 interacts with the rpa43 subunit of RNA polymerase I, and treatment with cycloheximide inhibits the formation of a RRN3/rpa43 complex in vivo (Alice H. Cavanaugh, et al., 2002. Rrn3 Phosphorylation is a regulatory checkpoint for ribosome biogenesis J. Biol. Chem., 2002; 277: 27423-27432).
PCT Application No. PCT/IL2007/32856 discloses methods and kits for predicting prognosis of multiple sclerosis.
PCT Application No. PCT/IL2007/001617 discloses methods and kits for predicting the prognosis of a subject diagnosed with multiple sclerosis and methods of selecting a treatment regimen of a subject diagnosed with multiple sclerosis.
Achiron A, et al., 2007 (Clinical and Experimental Immunology, 149: 235-242) describe genes of the zinc-ion binding and cytokine activity regulation pathways which predict outcome in relapsing-remitting multiple sclerosis.
Additional background art includes PCT Pub. No. WO03081201A2.